This report also dances around the exact location of the drone by saying it was 'in the vicinity' of an Israeli border town.
I read another report that suggests the drone was used to lure the Israeli F-16 into Syrian airspace before launching missiles at it, which would suggest a more sophisticated response (perhaps premeditated) than the Israelis were expecting.
Israel had no reason to attack a sovereign country. If that changes, i will say so.
That is was an ambush is the most prevalent theory at the moment, (given the large number of SA-5s in the air), and that the Russians may have been controlling the batteries. However, the drone did manage to gather a lot of intel about Israeli positions and comm along the border.